Not Applicable
This invention relates to an improved inspection and quality level sensing system for use during processing of webs such as paper, film, composites, or the like, in dynamic continuous processing operations. More particularly, the invention relates to sensing and assessing the location and quality condition of features, characteristics, and elements characteristic of personal care articles or precursors of such articles on an article fabrication line. The invention can sense and assess, for example, the location and quality of respective components, the location and quality of ultrasonic or thermal bonding, and/or the location and amount of adhesives present in a web of personal care article precursors during the fabrication of such personal care article precursors from suitable raw material inputs.
In assembling various elements on an e.g. endless web to make personal care articles, it is highly desirable to have a real-time inspection of various aspects of the articles being fabricated, including inspection of the articles at one or more locations on the fabrication line, as the articles are being fabricated and before fabrication is complete.
In the personal care article industry, it is known to use optical brighteners to mark components or portions of elements which form such articles in a fabrication line. When such optical brighteners are properly selected, properly applied, and properly positioned, the articles can be illuminated with ultraviolet light and/or visible light. Ultraviolet and visible light sensors can sense the optical brighteners so illuminated, and can thus record the positions, or relative positions, of components carrying such optical brighteners in such personal care articles. While some article elements can thus be detected, to applicants"" knowledge, it is not known to employ such procedures to assess presence and quality of adhesive or other bonds or bonding in the context of a personal care article.
In addition, applicants are aware that some, but not necessarily all, hot melt adhesives inherently fluoresce under ultraviolet light. However, applicants are not aware of any use of such property for detecting relative positioning of elements.
In other methods of assessing or predicting product quality, structural elements such as notches, slits, slots, protrusions, depressions, or holes or the like are formed in the web of personal care articles, thus to provide a detectable structural feature which can be used to sense location of an element.
A region of magnetic discontinuity, electromagnetic discontinuity, or any combination thereof may also be used with suitable sensors of magnetic properties to show the positions of components of respective personal care articles.
The above methods of assessing or predicting product quality require modifying the personal care articles specifically for the purpose of being able to sense or detect the parameters of interest, such as for example using additional material such as an optical brightener, or a magnetic additive, or modifying the structure of the personal care articles, in order to create an element detectable by the sensors selected for the detection function. Such modifications increase the cost of personal care articles, in addition to bearing the cost of the actual detection. Further, use of such additional material, elements, or features includes the risk that the additional material, elements, or features, may be misplaced in the web, or on the respective web element, and thus give a false reading to the sensing system. There is also the risk that such modification to the product or product component may interfere with either the intended use of the personal care article or the safety of a person using the personal care article for the intended use.
It would be desired that no such additional material element, or feature, need be incorporated into or added to any element or feature of the articles being fabricated.
In the invention, process heat with which the workpiece elements are inherently imbued by the process, is detected by one or more infrared sensors which sense the thermal condition inherent in a plurality of characteristics of respective features of the personal care articles being formed, and wherein the features so sensed generally have primary utility in the typical functioning of the article, and are not incorporated into the article merely to assist in the sensing operation. Characteristics which are sensed are, for example, individual components, and parts of components, of the personal care article, ultrasonic bonds, and adhesive at bonds. With proper resolution in a display of the properties so sensed, sensing such elements can pinpoint or show the exact location of such individual components, or adhesive, or ultrasonic or other thermally-formed bonds. The sensed information can be compared to stored or other reference information to determine whether or not the respective components or bonds are disposed at desired or specified locations on respective personal care articles.
The sensed information also can be compared with stored or other reference information to determine whether or not the qualities or strengths of ultrasonic bonds are effective to maintain the structural integrity of the respective personal care articles.
Further, the sensed infrared information can be compared with stored or other reference information to determine whether or not a sufficient quantity of adhesive, such as hot melt adhesive, has been applied to the personal care articles being fabricated and whether or not such adhesive has been properly distributed, in the proper relationships, on the respective components of the personal care articles.
The above comparisons can be reported to a fabrication line operator whereby the operator can monitor ongoing conformity with, or variance from, reference or other specified parameters. Variance outside specified tolerances can trigger an alarm to warn the operator that a malfunction has occurred. Further, the above comparisons can be used to cull unacceptable units of product from the personal care article fabrication line. Information from the above comparisons can also be used to shut down the processing line at certain predetermined levels of variance from specified parameters.
A significant advantage of the invention is that infrared sensors can sense the location of elements which are not readily susceptible to detection from the outside of the personal care article using sensors operating in the visible or ultraviolet wavelengths. Because of use of the infrared spectrum, the infrared system can see elements or components through one or more layers of material which are opaque to visible and/or ultraviolet light. Thus, assuming an infrared energy source, an infrared sensor can xe2x80x9csee throughxe2x80x9d e.g. cover layers or bodyside liners of material and can display visual images of elements or components thus xe2x80x9cseenxe2x80x9d or detected on the interior of the personal care article. In this manner, partially or fully assembled personal care articles can be viewed or inspected for defects which may be disposed under a visually opaque element. Processing apparatus, such as a digital computer, can process the received information and compare the information with reference or otherwise known tolerances and physical values for the various components, and positions of components.
The infrared sensor typically comprises a passive infrared sensor that senses, in the personal care article work product, or work product precursor, heat that is normally inherently present in the personal care article or work product or precursor as a result of the process of assembling such work product or precursor. The heat results from, for example, ultrasonic bonding, the application of hot melt adhesive to various components of personal care articles, and residual heat otherwise developed in others of the elements as the elements are prepared for, and incorporated into, the personal care articles being fabricated on the fabrication line.
For example, certain components, such as the absorbent core, and super-absorbent therein, are inherently heated, or can be heated, to temperatures different from the temperatures of other components whereby such elements can be distinguished on the basis of temperature differences. Namely, a component can be distinguished in the visual display by controlling temperature of the component such that the component emanates infrared radiation at a rate which is unique in the web, relative to other components of the personal care article precursor.
To the inventors"" knowledge, it is not known to utilize an infrared sensor to sense fibrous and/or thin-section polymeric films, fibers, or adhesives as components in a personal care article fabrication line, thereby to provide signals or information in response to the physical temperatures of components forming the personal care articles, especially where the property sensed, namely temperature, is the property inhering in the personal care article precursor in the fabrication line as a result of the manufacturing process, or manufacturing history, of the precursors. Of course, at conclusion of the manufacturing process, the personal care articles so produced continually give off heat according to temperature differentials between the personal care articles and ambient temperature, until the personal care articles reach ambient temperature. Thus, the infrared signatures of interest herein must be obtained while the personal care articles still contain discriminating amounts of such process heat.
Further to the inventors"" knowledge, it is not known to use an infrared sensor to sense infrared energy and thereby to create visual images corresponding to the presence or quantity of adhesives, or strength of ultrasonic bonds, on the personal care articles. Advantageously, warm adhesives can be seen by the infrared sensor through one or more intervening visually opaque layers of material in the personal care article.
The above reading of infrared signatures can be obtained by placing suitable assemblage of infrared sensor equipment at a single sensing location in the fabrication line. Multiple images of the articles being produced on the fabrication line can, of course, be obtained by placing suitable assemblages of infrared sensor equipment at a corresponding number of locations along the fabrication line, each of such assemblages having the capability of sensing the desired information at the respective locations in the fabrication line, from which a visual image can be created, separate and distinct from the visual images developed from sensings at other locations along the fabrication line. Such multiple images, taken from corresponding multiple locations on the fabrication line, can be compared to each other as desired for assessing either or both of (a) quality of the articles being produced, and (b) the satisfactory, or not, progression of the fabrication process along the fabrication line.
A first family of embodiments of the invention contemplates fabrication apparatus for fabricating composite personal care article products, and sensing assembly quality characteristics of the personal care article products so fabricated. At least one of the components of precursors of the personal care article products so fabricated comprises a continuous web of material. The fabrication apparatus comprises fabrication machinery arranged to transport the web along a fabrication line, past a plurality of work stations where work is performed on the web, for fabricating the personal care article precursors according to a predetermined arrangement, thereby to form an array of precursors of such personal care articles on the web; separation apparatus separating the web, and the array of personal care article precursors thereon, from the web, and into individual personal care articles, including severing the web across a transverse dimension thereof; and infrared sensing and signal processing apparatus disposed in cooperating relationship with the web. The infrared sensing and signal processing apparatus senses infrared signatures of product fabricated on the web, thereby determining assembly quality characteristics of respective ones of the composite personal care articles or composite personal care article precursors, and outputting a signal representative of the sensed characteristics.
In some embodiments, the infrared sensing and signal processing apparatus comprises an infrared sensor housed in a housing physically separate and distinct from the signal processing apparatus, such that the sensor and processing apparatus are two physically separate and distinct instruments. The processing apparatus receives a signal outputted from the infrared sensor and processes such signal to provide a processor output representative of the characteristics of at least one of the personal care articles or personal care article precursors fabricated on the fabrication line.
The fabrication machinery can place an absorbent core on the web, and a bodyside liner material over the absorbent core such that the absorbent core is between the web and the bodyside liner layer, and the infrared sensing and signal processing apparatus can view and sense the position of the absorbent core through the bodyside liner material, through the web, or through any other intervening material which may be visually obstructive, such as opaque, translucent, occlusive, or the like and that is not a thermally-effective barrier to detection by a thermal sensor or other thermal detection unit.
As another expression of the invention, the bodyside liner material can have a visual printed image on a first surface thereof between the infrared sensor and an assembly quality characteristic under the respective one of the bodyside liner material and the web, the sensing by the infrared sensor sensing an assembly quality characteristic through the visual printed image.
The invention also comprehends securement apparatus such as ultrasonic bonding apparatus or adhesive bonding apparatus securing at least portions of the respective components of the personal care articles to each other to form the composite personal care article precursors in a continuous web of such precursors joined to each other along a length of the web. Thus, the invention comprehends adhesive application apparatus applying adhesive for securing at least first portions of first respective components of the personal care articles to second portions of second respective ones of the components.
In some embodiments, the infrared sensor senses the position of adhesive in such personal care articles. In addition or in the alternative, the infrared sensor senses quantities of adhesive disposed in such personal care articles.
The personal care articles can include leg elastic placement apparatus placing spaced leg elastics adjacent respective opposing outside edges of leg cut-outs of the web along the lengths of the personal care articles, and adhering the leg elastics to components of the web or on the web. Adhesive apparatus can place hot melt adhesive on the leg elastics, the infrared sensor sensing the position of the heated hot melt adhesive on the leg elastic and thus indirectly detecting the positions of the leg elastics on the personal care articles by way of the warm hot melt adhesive.
In preferred embodiments, the bodyside liner material is disposed between the infrared sensor and the leg elastics, and the infrared sensor senses the positions of the adhesive, and thus the positions of the leg elastics, through the bodyside liner material.
In some embodiments, the absorbent cores have zones comprising relative concentrations of superabsorbent, and the infrared sensor senses the zones of relative concentration of superabsorbent as distinct from the remainders of the absorbent cores.
In some embodiments, the fabrication machinery places containment flaps over the web, preferably over the bodyside liner material, as elements of the personal care article precursors. The containment flaps are secured in the web by heated hot melt adhesive or other thermal or ultrasonic bonding. The infrared sensor senses position and quantity of the heated hot melt adhesive or other thermal or ultrasonic bonding.
The securement apparatus preferably comprises an ultrasonic horn and cooperating anvil, such as an anvil roll, the ultrasonic horn providing ultrasonic energy to create bonds bonding, in the personal care article precursors, at least one component of such personal care article precursors.
The infrared sensor preferably senses the positions of the still-warm ultrasonic bonds. The output of the infrared sensor can provide an indication to an operator station when the infrared sensor does not detect the presence of the ultrasonic bonds.
Among other potential readings, the infrared sensor and signal processing apparatus can sense registration of predetermined ones of the components, either against a design location stored in memory or, relatively, against the location of a second component or other element, characteristic of the articles, e.g. an adhesive or ultrasonic bond.
The output of the infrared sensing and signal processing apparatus can send an alarm signal to an operator station identifying existence of an improper condition for at least one of the components, or can output a cull signal to cull selected ones of the personal care articles from the fabrication line, or can shut down the fabrication line, or can issue a control command, and thereby activates a registration control function.
Stated another way, the output of the infrared sensing and signal processing apparatus can call attention, in various ways, to characteristics or components of the personal care articles that are not within preselected control tolerances.
The infrared sensing and signal processing apparatus can sense the presence of leg cut-outs on the personal care articles, and control an alarm to an operator station.
Typically, the infrared sensing and signal processing apparatus senses and assesses assembly quality characteristics common to all of the personal care articles being fabricated on the fabrication line, the assembly quality characteristics, in combination, comprising a signature for the specific personal care articles being fabricated.
Preferably, the infrared sensing and signal processing apparatus has a sensitivity suitable for sensing, and thus senses, portions, or entireties, of personal care articles having temperatures as low as about 10 degrees Celsius and up to about 200 degrees Celsius.
Preferably, the infrared sensor is a single sensor or sensor array, operating in a passive mode, whereby no illuminating energy is directed toward the material being sensed. Rather, the sensor senses temperatures and differences across the overall projected surface defined by an area of one or more of the personal care articles.
Typically, the infrared sensing and signal processing apparatus comprises an infrared camera collecting infrared images from the personal care articles. Typical cameras effective to detect and distinguish infrared radiation are controlled by the electronic and optical filtering elements of the camera, or of one or more suitable camera attachments.
In preferred embodiments, the output from the infrared sensing and signal processing apparatus comprises a composite visual image representative of at least one of the personal care articles or personal care article precursors on the web. Typically, the infrared sensor comprises an infrared camera collecting, for each visual image which can be displayed, an array of infrared signals from discrete areas of the personal care articles being assessed.
The output of the infrared sensing and signal processing apparatus can represent an out-of-tolerance condition in the personal care article or personal care article precursor sensed, and wherein the infrared sensing and signal processing apparatus sends the out-of-tolerance signal to an operator station.
In preferred embodiments, the infrared sensing and signal processing apparatus comprises visual image processing apparatus.
More specifically the fabrication machinery used in fabricating personal care articles according to the invention can further comprise a first layer device and a first turning device, feeding the web into the fabrication line; an absorbent core device feeding absorbent cores to the web in the fabrication line; a second layer device and a second turning device, feeding a second outer layer into the fabrication line and over the first layer and the absorbent cover; a leg elastics device feeding leg elastics into the fabrication line; a containment flap device feeding containment flaps into the fabrication line above the second outer layer: a first bonding device applying generally continuous bonds along opposing sides of the web along substantially the entirety of the length of the web downstream from the bonding device; a second bonding device applying end seals along ends of the respective personal care article precursors; a first adhesive application device applying adhesive to the leg elastics, thereby to adhere the leg elastics in the personal care article precursors; a tape storage device feeding tapes into the fabrication line; a second adhesive application device applying adhesive to the tapes, thereby to adhere the tapes in the personal care article precursors; and a third adhesive application device applying adhesive to the containment flaps, thereby to adhere the containment flaps in the personal care article precursors over the absorbent core.
In a second family of embodiments, the invention comprehends a method of sensing assembly quality characteristics of a web of personal care articles or personal care article precursors being fabricated by processing apparatus. Each such personal care article or personal care article precursor has a bodyside liner, an outer cover, and at least one element of the personal care article or personal care article precursor disposed between the bodyside liner and the outer cover. The method comprises using infrared sensing and signal processing apparatus employing an infrared sensor, sensing assembly quality characteristics of an element, typically an element between the bodyside liner and the outer cover, through a visually relatively opaque one of the outer cover and the bodyside liner, and outputting first signals from the infrared sensor; and sending the outputted signals to an element of the infrared sensing and signal processing apparatus which can respond by outputting second signals indicative of assembly quality characteristics of the personal care articles or personal care article precursors being fabricated by the processing apparatus.
Preferred embodiments include maintaining the personal care articles free from fluorescent material, especially fluorescent materials and other additives for optical brightening as used for detection purposes, throughout the process of fabricating the personal care articles.
A third family of embodiments comprehends a method of fabricating composite personal care article products wherein at least one of the components of precursors of the personal care article products so fabricated comprises a continuous web of material, and wherein the method comprises transporting the web along a fabrication line, past a plurality of work stations where work is performed on the web, for fabricating the personal care article precursors according to a predetermined arrangement, thereby to form an array of precursors of such personal care articles on the web; separating web segments, and the array of personal care article precursors thereon, from the web, and into individual personal care articles, including severing the web across a transverse dimension thereof; and sensing infrared signatures of product fabricated on the web, thereby determining assembly quality characteristics of respective ones of the composite personal care articles or composite personal care article precursors, and outputting a signal representative of the sensed characteristics.
In a fourth family of embodiments, the invention comprehends using fabrication apparatus comprising infrared sensing apparatus disposed in cooperating relationship with the web, the infrared sensing apparatus being capable of sensing infrared properties of product being fabricated on the web, and capable of outputting signals indicative of infrared signatures of product being fabricated on the web. The fabrication apparatus also comprises visual image processing apparatus communicatively connected to the infrared sensing apparatus, and capable of accepting such outputted signals indicative of infrared signatures of product being fabricated on the web, and processing such data and thereby determining assembly quality characteristics of respective ones of the composite personal care articles or composite personal care article precursors.
In some embodiments, the signals indicative of infrared signature data outputted from the infrared sensing apparatus are in video format acceptable for processing in the visual image processing apparatus.
In preferred embodiments, the visual image processing apparatus comprises a computer module capable of comparing image data from the infrared sensing apparatus with preselected stored images.
In some embodiments, the visual image processing apparatus outputs, to an operator station display, signals indicative of visual images and derived from the infrared signatures.
The operator station display can also concurrently show respective preselected stored visual image information.
In preferred embodiments, the visual image processing apparatus compares image data for a given personal care article on the web against a predetermined data standard thereby determining conformance of the respective personal care article to the standard, and optionally outputting cull signals to cull selected ones of such compared personal care articles from the fabrication line.
In some embodiments, the visual image processing apparatus can output one or more of a fabrication line shutdown signal, a signal which calls attention to characteristics of the personal care articles not within preselected control tolerances, and a signal which activates process adjustments to adjust characteristics of the personal care articles, where such characteristics are not within preselected control tolerances before adjustment.
In a fifth family of embodiments, the invention comprehends, using visual image processing apparatus, accepting outputted signals indicative of infrared signatures of product being fabricated on the web, and processing such data and displaying the data as visual images by visual image display apparatus.
In a sixth family of embodiments, the invention comprehends a method of sensing assembly quality characteristics of a web of personal care articles or personal care article precursors being fabricated on a fabrication line by processing apparatus, wherein each personal care article or personal care article precursor has, as an element thereof, a bodyside liner, an outer cover, and at least one element of the personal care article or personal care article precursor disposed between the bodyside liner and the outer cover. The method comprises sensing infrared properties of product being fabricated on the web using infrared sensing apparatus, and outputting signals indicative of infrared properties of product being fabricated on the web to image processing apparatus. The method also comprises creating a database comprising infrared properties of product standards within selected control tolerances. Additionally, the method comprises comparing infrared properties of product being fabricated with the database data using the image processing apparatus, including a programmable logic controller capable of comparing image data from the infrared sensing apparatus with preselected stored data in the database. The method also comprises outputting processing adjustment signals from the programmable logic controller to processing apparatus of the fabrication line to effect adjustment of absorbent article processing.
In some embodiments, signals indicative of infrared properties of product being fabricated on the web are outputted in video format acceptable for processing in the visual image processing apparatus.
In some embodiments, the method includes outputting signals indicative of visual images, derived from the infrared signatures, to an operator station display using the visual image processing apparatus.
In preferred embodiments, the method includes comparing visual image data for a given personal care article on the web against a predetermined data standard and thereby determining conformance of the respective personal care article to the standard, and outputting cull or other signals to cull or otherwise manipulate selected ones of such compared personal care articles on the fabrication line.
In some embodiments, the method includes the visual image processing apparatus outputting one or more of the signals selected from the group consisting of a fabrication line shutdown signal, signal which calls attention to characteristics of the personal care articles not within preselected control tolerances, and a signal which activates process adjustments to adjust characteristics of the personal care articles, such characteristics not being within preselected control tolerances before adjustment.